Digital signage systems and networks make use of display screens that are controlled to present different manners of content. Often these systems display advertising materials, and are part of a network of displays on which an advertiser can buy display time. The displays are often controlled by computer systems and are presented to a viewer in such a fashion that it appears that the screen is an autonomous device. Digital signage is used for a number of other purposes including corporate displays used to provide information and direction to users, industrial displays used to display real time production data, conference displays used to display upcoming meetings, airport displays that provide incoming flight information as well as numerous other uses known to those skilled in the art.
Prior art digital signage networks and systems are deployed with the objective of optimizing a limited network to deliver a particular type of data that is considered to be the primary driver of content. Thus, if a system is designed for playback of video, other information types such as stock tickers, weather forecasts or static (or statically revolving) still images receive a lower transmission priority in the network. If systems employ control mechanisms that allow display feedback and centralized control, the control data is often assigned the lowest priority of all data types, as this information is not seen as driving revenues.
Conventional digital signage is either based around a template, or a full screen video playback. Template driven implementations employ templates to define the type of content displayed in portions of the screen. The templates also define background patterns and other look and feel implementations. Each region of the screen is typically employed for a different type of data, so a video may play in a portion of the screen, while a weather forecast is displayed in a second portion, and a stock ticker or news crawl is run in a third portion. Each portion of the screen is thus segmented on the basis of its data type or the input stream. Full screen playback implementations typically make use of a pre-recorded video stream that is played in a loop, and updated periodically. These systems do not typically rely on live data, and though they may appear to rely on a template, the appearance of the template is a part of the video stream.
Control of the distributed nodes in prior art digital signage systems has typically been directed to the distribution of advertising content to displays from a central content source, while communications from the displays to a central server are commonly directed to providing audit information to confirm that advertisements have been played. Each display in the network is typically provided an address, and programming of the display is managed from the central content source. This central provisioning allows control of the content to be maintained. When location specific data, such as weather forecasts, is transmitted to displays, it is commonly done in one of two ways. The centralized provisioning of the display can be set to ensure that the correct location specific data is extracted from a collection of all location specific data and then transmitted to the individual display. Though this is a transmission efficient mechanism, it relies upon centralized administration that becomes onerous as more displays are added. Furthermore, if displays are relocated to different locations, the new location data must be reset centrally to ensure that the correct location specific data is transmitted to the screen. In an alternate solution, the location is programmed into the display, and the collection of all location specific data is transmitted to the display. This allows for a much easier provisioning, as centralized control no longer needs to ensure that a specific data stream is sent to the display. Unfortunately, this easy to administer approach results in the consumption of large amounts of bandwidth. This becomes a problem as the signage network grows, and a centralized server is responsible for transmitting unnecessary data to each display.
Conventionally, if a display is provisioned to retrieve only its location specific data, the display generates traffic on the network when it checks to see if new data is available on the content server. This polling of a centralized content server generates a small amount of traffic, but as the number of nodes in the network grows, the bandwidth consumed by this polling increases. Unless the time gap between polling events is increased as the network increases in size, the scalability of the system decreases.
Existing advertising networks rely on central provisioning for a number of reasons, but one of the foremost reasons is that with the correct provisioning tools, the administrator of a subset of the overall network could errantly program the displays on another portion of the network. The provisioning tools are thus created in various versions so that the central authority can access all functions and devices, and so that administrators of subsets are provided certain access rights to the screens they have authority over. This allows for centralized control, but results in great difficulty if a small number of screens are needed to display a customized selection of data, or are needed to use a customized template specific only to those screens.
Communications between the displays and the centralized content sources in existing display networks tend to be direct connections. Each node directly obtains content from the centralized data source, requiring that the centralized data source be able to support a high bandwidth connection open to all the nodes. When new nodes are added, they are provided an address at which the server can connect to them. The balance of the provisioning is performed as a server side task. This centralization provides the administrator of the network with the knowledge of all nodes in a network as no node receives data without being centrally provisioned.
Animation effects and rendering of content is often pre-prepared centrally and distributed to the displays from the central content source. The rendering of the prepared video stream is done locally as it is often display specific. Content is restricted to the section of a display template that it is designed for. Overlaying one type of data on another (e.g. a translucent text display over a video stream) is achieved by creating a flattened video stream at the content source and then distributing the flattened content to the display. This simplifies the rendering functionality employed at the display nodes, but results in an inability to have live data displayed in anything other than a specifically defined portion of a template.
The design decisions made in existing networks of digital signage displays have been made for a number of differing design decisions. Often the objective is to achieve a uniformity that eases administration and reduces the likelihood of a display being out of order. These systems were often designed for smaller distributions of screens. Networks that claim to have a common administrator often have distinct infrastructures to avoid bottlenecks, and to allow for better network specific templates and content issues.
It is, therefore, desirable to provide a digital display network having nodes that reduce the unnecessary consumption of bandwidth and provide additional flexibility in the rendering of content and manner in which they are provisioned.